Valve-seat facing tool



Dec. 31, 1935,

H. M. ALBEE VALVE SEAT FACING TIOOL Filed Oct. 10, 1934 I aweaaioa 05 M cfiZZree, I M r/W viii/f9 Patented Dec. 31, 1935 PATENT OFFICE VALVE-SEAT FACING TOOL Hugh M. Albee, Orange, Mass, assignor to The Leavitt Machine Company, Orange, Mass, a corporation of Massachusetts Application October 10, 1934, Serial No. 747,705

3 Claims.

This invention relates to valve-seat facing tools of the class in which a rotary cutter head is rotated step by step by a to-and-fro swinging movement of a lever connected to a friction band wrapped about the cutter head and alternately contracted and relaxed by the movement of the lever. The invention aims to reduce the number of parts of the operating mechanism as compared with other tools of this nature and to prevent bending and consequent crystallization of the band adjacent to the points of attachment of the ends of the band. 'This invention is in the nature of an improvement upon and a simplification of the rotating mechanism disclosed in Letters Patent No. 1,851,613 issued to The Leavitt Machine Company as my assignee.

The invention will best be understood by reference to the following description when taken in connection with the accompanying drawing of one specific embodiment thereof, while its scope will be pointed out more particularly in the appended claims.

In the drawing: Fig. 1 is a front elevation partly in vertical section of a valve-seat facing tool embodying the inon line 2--2 of Fig. 1.

Referring to the drawing and to the embodiment of the invention illustrated therein by way of example, there is shown a valve-seat facing tool comprising a cutter head in the nature of a disk 3 to which appropriate cutters 5 are suitably attached. The head is provided with a pcripheral groove I in which is a band 9 wrapped about and frictionally engaging the head.

The mechanism now to be described utilizes the band to rotate the head step by step. This mechanism includes a friction shoe I I having an armate portion [3 which is received within the groove 1 and has a toe IE to rock upon the-cutter head as a fulcrum. To this shoe a handle I! is rigidly afiixed, and thus, when the handle and the shoe are rocked toward the left as viewed in Fig. 1, they constitute a lever which rocks about a fulcrum other than the center of rotation of the head. The lever is directly and pivotally attached to both ends of theband at points differentially related to the center of the band to cause the band to be contracted and to rotate the head when the lever is rocked on the fulcrum in one direction, and to be relaxed when the lever is rocked in the opposite direction.

In the example shown, the band has relatively long and short terminal portions, and the latter mensions of this passage being such that the ter- 10 minal portion does not contact, with the sides of the passage, and hence there can be no bending and consequent crystallization of the hand. Then too, the absence of bending is advantageous because of the consequent lack of resistance to swinging of the lever. 1

As herein shown, the relatively long terminal portion of the band is pivotally attached to the shoe by a rocking pivot 2'! herein conveniently in the form of a sphere which-is loosely received in an aperture 29 in the shoe and is capable of rocking to and fro in a seat 3| at the lower portion of the aperture. This pivot, for purposes of adjustment of the band, is adjustably mounted on and about the adjacent terminal portion of the band as by having screw threaded engagement therewith. The relatively long terminal portion of the band extends loosely through a passage 33 which extends from the aperture 29 through the shoe to a point adjacent the toe l5 of the shoe, the diameter of this passage being such that the terminal portion of the band does not contact with the sides of the passage, and hence there can be no bending and consequent crystallization of the band. This is, of course, due to the rocking action of the pivot 21.

Rotation of the rocking member 21 to eifect adjustment of the band is conveniently accomplished by the use of a rod inserted into any one of a series of openings 35 provided in the rocking pivot. Accidental rotation of the rocking member on the band terminal is prevented by appropriate means, herein a screw 37, threaded into the shoe and engaging the rocking pivot 21. This screw engages the rocking member with only sufficient force to prevent the adjustment from being disturbed, but without in any way interfering with the rocking action of the pivot.

In operation the handle I1 is grasped and swung toward the left as viewed in Fig. l. The resistance of the work to rotation of the cutter head results in a rocking action of the lever. The shoe swings about a center in the region of the pivot 23 until the shoe is pressed against the periphery of the cutter head 3, whereupon a pull is exerted upon the longer terminal portion of the band toward the left as viewed in Fig. 1, and hence contracting the band about the cutter head. Thereupon the shoe, the band and the cutter head rotate as a unit about the center of rotation of the cutter head because of the frictional engagement of the band and the shoe with the peripheral surface of the cutter head. When, on the other hand, the handle is swung in the opposite direction, the longer terminal portion of the band is slackened, the band is relaxed and the band and the shoe travel freely about the axis of the cutter head without rotating the latter backward, it being understood, of course, that the resistance presented by the work is sufficient to hold the cutter head against reverse rotation.

No spring is required to assist in relaxing the band, and the number of other parts is reduced to a minimum by the direct connection of the, band to the operating lever. As already indicated, the free pivotal connection of the band terminals with the lever results not only in a free rocking movement of the latter, but also prevents bending and consequent crystallization of the band terminals.

Having thus described one embodiment of the invention, but without limiting myself thereto, what I claim and desire by Letters Patent to secure is:

1. In a tool of the class described, to be applied to a rotatable body provided with a peripheral groove, a. band consisting of a rod to be received in-said groove and having a relatively long and a relatively short terminal portion, said short terminal portion being formed as an eye, and said long terminal portion being provided with a screw thread, and means for utilizing said band to rotate said body step by step in one direction only, said means comprising a friction shoe having an arcuate portion to be received within said groove and having a toe to rock upon said body as a fulcrum adjacent said long terminal portion, said shoe being provided with an aperture therethrough and a passage through which said long terminal portion extends loosely into said aperture, said shoe being provided also with a chamber within which said eye is received, a rocking pivot which is threaded onto said screw thread and is loosely received in said aperture to rock therein, and a pivot extending through said eye within said chamber.

2. In a tool of the class described, to be applied to a rotatable body having a peripheral surface, a band consisting of a rod to be disposed about said surface and having a relatively long and a relatively short terminal portion, said short terminal portion being formed as an eye, and said long terminal portion being provided with a screw thread, and means for utilizing said band to rotate said body step by step in one direction only, said means comprising a friction shoe presenting an arcuate surface having a toe to rock upon said surface as a fulcrum adjacent said long terminal portion, said shoe being provided with an aperture therethrough and with a passage through which said long terminal portion extends loosely into said aperture, said shoe being provided mso with a chamber in which said eye is received, a rocking pivot which is threaded onto said screw thread and is loosely received in said aperture to rock therein, and a pivot extending through said eye within said chamber.

3. In a tool of the class described, to be applied to a rotatable body having a peripheral surface, a band consisting of a rod to be disposed about said surface and having a relatively long and a relatively short terminal portion, said short terminal portion being formed as an eye,

and said long terminal portion being provided with a screw thread, and means for utilizing said band to rotate said body step by step in one direction only, said means comprising a friction shoe presenting an arcuate surface having a toe to rock upon said surface as a fulcrum adjacent said long terminal portion, said shoe being provided with an aperture therethrough and with a passage through which said long terminal portion extends loosely into said aperture, said shoe being provided also with a chamber in which said eye is received, a rocking pivot which is in the form of a sphere which is threaded onto said screw thread and is loosely received in said aperture and is capable of rocking to and fro on a seat within said aperture, said sphere being provided with a series of openings for the insertion of a rod to rotate the same, and a pivot extendingthrough said eye within said chamber.

HUGH M. ALBEE. 

